Apparatus and method for continuous casting of ingots having longitudinal channels and spacer member therein



C. E. MAIER ETAL June 9. 1964 APPARATUS AND METHOD FOR CONTINUOUSCARTING OF INGOTS HAVING LONGITUDINAL. CHANNELS AND SPACER MEMBERTHEREIN Filed June 20, 1960 5 Sheets-Sheet 1 a F W 2 E @E LJILAINVENTORS Cum-n s E..MA\EQ giflZoeEzr MBzmn BY 7mm, 9, 0%

ATTO IZN EY5 June 9, 1964 c MAIER ETAL 3,136,008

APPARATUS AND METHOD FOR CONTINUOUS CARTING OF INGOTS HAVINGLONGITUDINAL CHANNELS AND SPACER MEMBER THEREIN Filed June 20, 1960 5Sheets-Sheet 2 8 I 255i kzfiqo '30 $5 32 i w I i: a; a \g TIE-.5 s hATTOQHEYS June '9. 1964 c. E. MAIER ETAL 3,135,003

APPARATUS AND METHOD FOR CONTINUOUS CARTING OF INGOTS HAVINGLONGITUDINAL CHANNELS AND SPACER MEMBER THEREIN Filed June 20, 1960 5Sheets-Sheet 3 4 TIE-.EA 744 34 aeoomae e INVENTORJ' Cum-us E. Mmazy20522.1 MBmcvc AT TQQMEY$ June 9, 196 c. E. MAIER ETAL APPARATUS ANDMETHOD FOR CONTINUOUS CART'ING OF INGOTS HAVING LONGITUD-INAL CHANNELSAND SPACER MEMBER THEREIN Filed June 20, 1960 5 Sheets-Sheet 4 TIE--15 m5 /J r 5 o O m q /q o 4 o s q 0 INVENTORS Cwzrn s EMMEZ EJ205221 VLBmcKQM M 5m,

ATToQUt-IYS June 9', 1964 c. E. MAIER ETAL 3,136,008 APPARATUS ANDMETHOD FOR CONTINUOUS CARTING 20F INGOTS HAVING LONGITUDINAL CHANNELSAND SPACER MEMBER THEREIN 5 Sheets-Sheet 5 Filed June 20, 1960 an. an:m: ma.

INVENTORJ C u 2115 E. Mmaz & Eosem' H. BraucK BY w, rva @AJA aw dATTORNEYS United States Patent 3,136,008 APPARATUS AND METHOD FORC(DNTINUOUS (IASTING 0F INGOTS HAVING LQNGITUDINAL CI IANNELS AND SPAQERMEMBER THEREEN Curtis E. Maier, Riverside, and Robert M. Brick, H1115-dale, 111., assignors to Continental Can Company, Inc., New York, N.Y.,a corporation of New York Filed June 20, 1960, Ser. No. 37,267 8 Claims.(Cl. 22-572) This invention relates to the production of hollow bodiessuch as tubes by rolling an internally channelled billet into laminatestrip, and then separating laminations of the strip to form the body.

An object of the invention is the production of an ingot having channelsprovided by cores fixed relative to the ingot mold, with the feeding ofspacer pieces between the cores for bonding to the ingot metal.

Another object is the provision of apparatus for the production ofingots having internal channels separated from one another by metalspacers separately fed to the ingot mold.

A further object is the production of an ingot having multiple internalchannels by employment of cooled cores fixed relative to the ingot mold,and having shapes for facilitating the movement of the cooling ingotmetal relative to the cores.

A further object is the production of a billet with open internalchannels and internal discontinuities between such channels which can berolled into a multi-wide strip stock, for trimming and severance intosingle-wide strips by overstressing at the regions of the residues ofthe discontinuities between the internal channels.

With these and other objects in view, as will appear in the course ofthe following description and claims, illustrative embodiment of theinvention is shown in the accompanying drawings, in which:

FIGURE 1 is an upright section through a conventionalized castingapparatus, with parts adapting it for the present invention;

FIGUREZ is a section substantially on line 2-2 of FIGURE 1, showing thepath of spacer pieces and ingot;

FIGURE 3 is a horizontal section of the mold with spacers and fixedcores therein, substantially on line 33 of FIGURE 1;

FIGURE 3A is a section corresponding to FIGURE 3, and showing theincorporation of pro-formed edge pieces;

FIGURE 4 is a fragmentary horizontal section, sub-' stantially on line44 of FIGURE 1, on an enlarged scale;

FIGURE 4A is a section corresponding to FIGURE 4, and showing thefeeding of edge pieces as in FIG- URE 3A;

FIGURE 5 is an upright section substantially on line 55 of FIGURE 4;

FIGURE 6 is an enlarged view of a part of FIGURE 2, with parts brokenaway to show cooling passages in a fixed core;

FIGURE 6A is a view corresponding to FIGURE 2, with the ingot inelevation, and showing the use and bonding of edge pieces as in FIGURES3A and 4A;

FIGURE 7 is a view corresponding to FIGURE 5, and showing a modifiedstructure;

FIGURE 8 is a perspective view showing the employment of brakes for apair of spacer guiding rollers;

FIGURE 9 is a perspective View of the lower end of a fixed core;

FIGURE 10 is a perspective view of one form of spacer piece;

FIGURES 10A, 10B and 10C show the engagement of core and spacer piecesduring the preparation of ingots;

3,136,008 Patented June 9, 1964 FIGURE 11 is a perspective view of theupper end of an ingot prepared with spacer pieces as in FIG- URE 10;

FIGURE 12 is a perspective view of another form of spacer piece;

FIGURE 13 is a view corresponding to the upper part of FIGURE 2, showingan arrangement for feeding spacer pieces as in FIGURE 12;

FIGURE 14 is a perspective view of the upper end of an ingot preparedwith spacer pieces as in FIGURE 12.

The invention has been illustrated by the preparation of ingots withfour channels, for making a four=wide rolled laminate strip; but isemployable for a desired even or odd number of such channels. Relativedimensions of width and thickness have been exaggerated for clearness.

In FIGURES 1 and 2 is conventionally shown a casting apparatusappropriate for the practice of this invention. A mold 20, open at topand bottom, has a cooling chamber 21 to which water can be delivered byaconduit 22 and removed by a conduit 23. At the beginning of a castingoperation, the bottom of the mold 20 is closed by a platform 24 whichcan be raised to closing position by a hydraulic ram. This ram has acylinder 25 and a piston 26: conduits from the upper and lower ends ofthe cylinder lead to a valve 27 which can be operated to pass fluidunder pressure from a supply pipe 28 to the lower end of the cylinderfor raising the platform, or to the upper end of the cylinder to permitor facilitate the downward movement, with respective discharge from theother cylinder end by pipe 29. I

Brackets 30 are connected with the mold 20 with inclusion of cushions 31which permit limited relative movements. These brackets carry a coresupport 32 above the upper end of the mold: and frame pieces 33 whichsupport guide rollers 34 for spacer inserts as set out hereinafter. Avibrator 35 is connected to the core support 32 to give the same limitedvibrations horizontally in the greater or width direction of the ingot,of around 0.001 inch. Such vibration creates shear motions at the partlysolidified interfaces of the wider parts of the cores and impingement atthe spacer interfaces, to minimize sticking to the fixed cores and toassist in the metal bonding or welding of the molten metal to the spacerpieces.

The core support 32 and guide rollers 34 receive the spacer inserts 41,FIGURE 1, and assure regular positioning and downward movement thereofinto and through the mold during a casting operation. A tundish 36 hasbifurcated branches at the sides of the spacers and the cores 40 whichare aligned with the spacers, and drop tubes by which the molten metalcan flow regularly downward into the mold without splashing or theformation of air bubbles. Flames from burners 38, FIGURE 1, may beemployed to raise the temperature of the inserted spacers 41 to assurethe weld-bonding.

The apparatus permits the casting of ingots having a desired number oflongitudinal channels therein, four being illustratively shown. InFIGURE 3, these channels are to be formed by the four fixed cores 40a,40b, 40c, 40d. Between and at the ends of these cores are providedspacer insert pieces 41a, 41b, 41c, 41d, 412 which can have longitudinalgrooves for receiving and being in guided relationship to the fixedcores. The spacer pieces 41a, etc., extend beyond the cores, and areshown as aligned with inwardly projecting ribs 42 on the mold walls.

The edges of the cores 49 are inter-fitted with the spacers; with thecore edgeshaving convergent edges, e.g., of rounded form but preferablyof a chisel-shape formed by convergent plane surfaces extending from'aradius of, say, & inch at the extreme edge and merging with the parallelmajor surfaces. The angle between the and molten ingot metals.

convergent plane surfaces can be between and 90 degrees: in practice,little difference has been observed the major wall surfaces 40s of thecore extend from the surfaces 66s of the spacers. In FIGURE 10B, theedge angle of the cores 40 is about 30 degrees, the spacers 66 have athickness of 0.125 inch with a groove angle of 30 degrees and depth of0.062 inch: wherewith the parts interfit and interlock but the materialof the spacer does not extend to the mergings of the convergent planesurfaces with the parallel wall surfaces 40s of the cores, and the ingotchannels have forms as in FIGURE 14. Curved concave grooves in thespacers 66, and conforming convex edges on the cores 40 may be employed,as shown in FIGURE 10C. In each case, the cores leave a channel ordiscontinuity and the spacers and poured metal provide integrated metalin the ingot which connects the ingot structure at the edges of eachchannel and between the adjacent channels: and this integrated metal hassuch a section that during rolling there is not present a slender columnof metal which may be distorted and bent laterally; with such shaped atthe cores and corresponding shapes of the longitudinal grooves in thespacers, the metal intervening between adjacent channels is then at thecenter of spacers and presents broad bases at the upper and lowersurfaces of the channels during rolling, and therewith the intercoremetal can be kept thin so that little trimming is needed upon the finsof the expanded tube produced therefrom.

The dihedral angle between the surfaces at the edges of the cores 40 maybe from 10 to 60 degrees, and may be as great as 90 degrees for someselections of spacer In practice with aluminum and aluminum alloys,angles of 14 and 28 degrees have been found satisfactory to prevent anyorange peel effect being formed when a liquid anti-welding resist ispresent during the early or break-down stages of hotrolling, such as mayoccur when the core edges are at right angles to the wider surfaces; andhave resulted in excellent control of the lamination widths.

One form of core support 32 is shown in FIGURES 4 and 5, where twoblocks 44, 45 can be clamped together by bolts 46 with the upper ends ofthe cores 40a, 40b, 40c, 40d held therebetween. Each block has a waterheader 47 or 48, to which water is delivered by a flexible metal supplypipe 49 or removed by a flexible metal pipe 50. The cores 40a, 40b, 40c,40d are made, FIGURES 3-5 and 9, with two longitudinal passages 51, 52therein. At the upper ends of each core, FIGURES 4 and 5, there arebranch passages which communicate respective ly with the headers 47, 48.Between the core positions, the blocks 44, 45 have cavities 53 forreceiving and guiding the spacer pieces 41a, 41b, 41c, 41d, 412.

In the modified form of core support, FIGURE 7, the individual core 40a,for example, has the two longitudinal passages, but these communicate atthe top for servicing with water by the inlet and outlet flexible metalpipes 49a, 50a which can be individually connected to water supply anddischarge headers for the several cores.

The procedure is adaptable to the employment of ingot metal which issubject to edge-cracking during rolling. In such cases, it is preferrredto provide edges on the billet which are of more ductile metal. Thus, inFIG- URE 3A, the parts of the composite ingot which are to form thelateral edges during rolling are constituted by pre-forrned edge pieces41x which may be of pure aluminum when the cast metal is of an aluminumalloy which is harder and less ductile during the rolling; or may beforged metal of the same analysis, e.g., forged 2024 alloy with the 2024alloy being poured, noting that cracking at and from the edges largelydevelops during the initial working from the cast structure to theworked structure. Therewith the burners 38a, FIGURE 6A, may be employedto heat the edge pieces 41x to a temperature close to the melting point,to assure the weld-bonding upon contact by the molten metal; andtherewith the edge pieces 41x have little resistance to bending so thatthey enter the mold and conform to the ingot metal being poured andsolidifying. Also, rollers 34a may be employed to engage the ingot belowthe mold, and preserve integrity of the structure and prevent rupture ofthe weld bond during the solidification by the action of shrinkageforces and any resistance to bending of the edge pieces. During thecasting, these edge pieces 41x as well as the spacers 41 becomeintegrated into the ingot, by the bonding of the molten metal to theexposed surfaces of these parts: therewith, the material for the edgepieces is of metal which can intermix with the casting metal so that thebond extends over the entire interfaces, with preference for having thebase metal of the edge pieces the same as the base for the cast metal,e.g., aluminum or a soft aluminum alloy when the cast metal is a hardaluminum alloy, copper when the cast metal is a tin or silicon bronze.Thus, the edge pieces 41x can be of the same analysis and prepared inthe same way as the spacers 41 for a given cast metal. During thesubsequent rolling, these edge pieces 41x are reduced with the caststructure, and therewith serve to maintain the cast metal under tri'axial compression during passage between the rolls, rather than uniaxialcompression at the edges as occurs when the edges of the cast metal areexposed and free during rolling.

For this, as shown in FIGURE 4A, the core support has the blocks 44, 45shaped for the passage of the edge pieces as well as the spacers 40, andsupports the cores 41 with delivery of cooling medium thereto andremoval therefrom by conduits 49, 50.

The several cores 40, FIGURE 9, are tapered so that the outer surfacesconverge downwardly in both the thickness and the width of the core.This tapering is shown as extending from the lower ends of the cores topoints above the mold, to permit changes of molten liquid level duringthe pouring: and the angle of convergence is selected in accordance withthe shrinkage of the ingot metal during cooling from molten to solidcondition, and during its further contact with the core: for aluminumand aluminum alloys, the angle can be between 8 degrees and one degreedependent upon the ingot composition and its thermal contraction factor,the thermal contraction of the core material, and the distance ofcontact. These cores can be prepared for facile freeing from the ingotas the latter moves downward: and can be easily replaced or interchangedin the support 32. The passages 51, 52

can be formed by drilling, or by casting core body material upon pipesfor providing the passages. The passages, FIGURES 6 and 9, arecross-connected near their lower ends so that water can flow downward inone passage and then upward in the other. In FIGURE 6, the lower ends ofthe passages and the cross-connection are illustratively shown as closedby a sealing plug 54.

When ingots of other than aluminum and aluminum alloys are to be made,the material for the cores is selected for its non-welding with themolten metal. With steel, the cores can have graphite surfaces, forexample, by forming them as porous graphite bodies having a passagetherein closed at the bottom, and with an oil under pressure beingforced into the passages so that it oozes from the surface and providesa lubricant for the downward movement of the solidifying steel and alsoprovides protection against oxidation of the cores. This employment ofoil is also useful with aluminum and other metals: the mold wall can becoated with oily grease before the pouring is started, and the supplyreplenished from time to time by applying the grease to the parts of themold wall above the liquid level; and acts to prevent sticking.

The cores 40 preferably not only taper in thickness and width; but also,FIGURE 6, they are convergent relative to one another. FIGURE 6 showssuch angular relationship in exaggerated form, for clearness; andindicates the relationships at th top 55 of the liquid level in themold, compared to the shrunken size of the ingot at the line 56 where itapproaches a temperature of, say, 800 to 1,000 degrees F.; noting that,at completion of a casting operation, the ingot may still have atemperature above 400 degrees F. at its end in contact with the platform 24. This tapering, and the effects of vibration when employed,permit the ingot to slide downward along the cores, without compressionthereon which might cause the ingot to remain suspended thereon. Thespacer pieces 41a, 41b, 41c, 41d, 41a are heated as they move downwardtoward the mold, and increase in size, with the distance between thecores selected to accommodate them: as the spacer pieces pass throughthe molten metal zone, they cool with the ingot and contract again, thisalso being provided for by having the shapes and positions of the coresto correspond. In practice, the molten metal chills and provides asolidified structure adjacent the cooled mold walls and the cooled fixedcores, while other parts of the metal solidify later during the downwardmovement, as shown by the curved dash lines 57 in FIGURE 1. With mostmolten metals, there is a sudden shrinkage during the change from liquidto solid state, followed by further shrinkage as the temperature of thesolidified metal drops. This behavior is conventionalized in FIGURE 5,where the molten liquid level 55 is at an upper part of the mold, andthe wall-solidification occurs down to the line 58 at which thesolidifying of the bosom of the metal causes shrinkage to becomesignificant, with the further contraction down to the line 56representing the thermal shrinkage of the solidified metal, the amountof contractions being exaggerated for clearness.

The cores 40a, 40b, 40c, 40d extend from the support 32 above the mold20 down into the mold to a depth at which the solidified surfaceportions of the ingot are strong enough to be self-sustaining. As shownin FIGURES l and 6, the lower ends of the cores are preferably above thebottom of the mold; and further cooling of the ingot as it emerges fromthe mold may be accomplished by jets of cooling water from the nozzles59.

In operation, the spacer pieces 41a, 41b, 41c, 41d, 41c are guideddownward in alignment with the cores 40a, 40b, and preferably areconnected to the platform 24. Thus the lower end of the spacer piece maybe tapered to make a tight, liquid-sealing fit in a mating aperture inthe platform, FIGURE 1, and secured as by a wedge 60.

The spacer pieces 41a, 41b, 41c, 41d, 41c are guided and controlledabove the mold by the rollers 34. It is preferred to have the piecesunder tension, whichis illustratively effected by the brakes 61, FIGURE8, bearing upon the rollers 34 for the spacer 41a.

The spacer pieces 41a, 41b, 41c, 41d, 41e may be stiff bars 41, FIGURE10, of metal which bonds to the molten ingot metal. Such strips, whensolid as in FIGURE 10, may have a width of 2 inches for an ingot whichis to be 8 inches thick and have channels inch or less thick; with astrip thickness of A inch, and longitudinal grooves of semicircularsection inch deep and of width to receive the edges of the cores. Thestrips may be made by extrusion, forging or rolling, with a forged orrolled structure preferred. The strips are cut to length andstraightened before use. With existing casting equipment for ingotsabout 14 feet long, the cut strips which are to be used as spacer piecescan be 15 feet long.

The spacer piece metal must be able to establish bonds with the moltenmetal brought into contact therewith. The metals may be of the sameanalysis, with low superheating of the molten metal above its meltingpoint, and

'6 by the cooling effects of the adjacent'fixed cores: the product is ahomogeneous metal in the rolled strip. The metals may be different: forexample, an aluminum alloy of high hardenability may be used for themolten ingot metal, and the spacer pieces may be of commercially purealuminum or of a softer aluminum alloy. When the spacer pieces are ofsofter material thanvthe cast metal for the laminations, these piecespermit theopening or expansion of the fixed strip and elimination of thereentraut angle to be accomplished, without cracking along the edges ofthe laminations. For example, when an aluminum alloy is being cast forthe major part of the ingot, the spacer pieces 41 can be of purealuminum rolled to the desired form. Therewith, the strip produced fromthe ingot will have the longitudinal portions which embrace the edges ofthe channel of metal which is more ductile than the portions whichprovide the laminations.

In the modified form of FIGURES 12 and 14, the spacer pieces 41 arecomposite. Two like strips 66, preferably of forged or rolled metal, andbondable to the molten ingot metal, each having a longitudinal groove 65therein. Prior to employment, a weld-preventing resist is applied to oneor both strips at the area where they are to be brought in contact: suchresist coating being shown by stippling 67 in FIGURE 12. Such strips maybe 0.125 inch thick, with grooves about 0.063 inch deep for receivingthe edge of the respective contacting core. These may be formed intocoils 70, FIGURE 13, and fed over turning rolls 71 into alignment withthe guide roll pairs 34 and thus into the cavities 53 of the coresupport. The anti-weld material can be supplied by nozzles 72 whichdeliver a smoky acetylenetorch flame against the side of the strip whichis to be prevented from welding: thereby a soot layer of 0.001 inch orless is deposited thereon.

It will be noted that the spacer piece which is employed for outer edgesof the lateral channels need have a groove at only the face whichcontacts the respective core. Thus, in FIGURE 14, only a single strip 66is employed at each side, with a weld-preventing coating at its outer,flat, surface 74, FIGURE 20. Correspondingly, in FIGURE 6, only theouter surfaces '74 of the spacer pieces 41a, 416 preferably have suchresist material.

While the assembly of fixed cores and spacer pieces will operate withfiat faces on the spacers, it is preferred to form the spacer pieceswith longitudinal grooves as shown, for preserving alignment of theparts, and to form the channels with rounded edges and with theinterfaces of the spacers and molten metal spaced from the edges of thelaminations provided in the rolled strip.

It is preferable to employ an agent for promoting the bonding of theliquid ingot metal to the spacer pieces. Thus, a mixture of halide saltscan be employed having a melting point below that of the ingot metal,and as an eutectic mixture of chlorides having a melting point around900 to 1,000 degrees F. With aluminum and aluminum alloys. It isfeasible to employ the bonding promoter'as fine particles in a volatilevehicle, and to apply the same to the spacer pieces before these enterthe mold, as by use of the rollers 34 for the purpose of delivering thincoatings to the transverse surfaces which are to be bonded.

For casting the ingot, the platform 24 is'raised by the ram 25, 26 toposition for sealing the bottom of the mold 20 and engaging the fixedcores. The spacer pieces 41 are introduced between and at the ends ofthe cores and are secured and sealed to the platform. Molten metal isthen admitted, until it forms a liquidlevel in the mold. A desirabletemperature of the molten metal is about 20 to 50 degrees F. above theliquidus or melting point for aluminum and its alloys. This initialmetal is permitted to cool and solidify, so that further molten metal iscontained. The ram is operated so that the ingot end moves downward: andthe rate of its movement and the pouring of metal by the tundish 36 iscoordinated so that the liquid level remains substantially constant inthe mold. As the ingot B moves downward, it leaves the fixed cores andhas channels as provided by these cores. The spacer pieces 41 becomeembedded in the initially cooled metal, and move downward through themolten metal, becoming bonded therewith so that they are integratedparts of the ingot: being guided by the cavities 53 in the core support32 and by the rollers 34 which are lightly braked to maintain a mildtension on the spacer pieces and hence hold them in position. The spacerpieces assure the presence of sound metal between the cores, and thusbetween the channels formed thereby: noting that the spacing between thecores may be 4; inch or less, so that the molten metal will not flowinto such crevices and fill the same adjacent the cold cores.

When the ram and platform approach their limit of travel, the pouring ofmetal is slowed and stopped. The ingots B produced are shown in FIGURES11 and 14. In FIGURE 11, solid spacer pieces, as in FIGURE 10, have beenused, with parts 80 thereof projecting at the upper end of the ingot,with channels 81 therebetween of a shape and size determined by thefixed cores. When the ribs 42 are employed on the mold walls, the ingothas correspondingly-shaped longitudinal grooves 82 on its surfaces. InFIGURE 14, the projecting ends 80 of the spacers show that the form ofFIGURE 12 has been employed.

The ingots can then be scalped and the internal channels provided withanti-welding material. They can then be hot and cold rolled to providestrips having internal discontinuities as residues of the channelsformed by the cores, between surface laminations of metal which areintegrally connected at the edges of such discontinuities; and withfurther internal discontinuities between the channel residues, whichpermit accurate severance of the strips along lines which are parallelto the edges of the channel residues and without intrusion into suchchannel residues.

The chisel-shape of the channels or discontinuities, as shown by thecores 40 in FIGURES A and 10B, is advantageous with resists which are inliquid form during the early or break-down passes of hot-rolling:therewith the liquid resist provides a coating for the internal surfacesand these surfaces approach one another without distortions such ascrinkling being present on the channel surfaces. With the curved edgesof FIGURE 10C, a solid resist can be introduced, preferably withvibration of the ingot to attain a uniform density of resist.

The illustrative practices shown are not restrictive; and the inventionmay be practiced in many ways within the scope of the appended claims.

What is claimed is:

1. The method of making an ingot having an internal longitudinal channelwhich comprises fixedly supporting a channel forming permanent coreabove a casting mold having a mold space with the upper and lower endsopen and with the lower ends of the core located in the mold space,holding spacer members in upright position and in abutment against theedges of the core so that the spacer members and core are locatedessentially in a first plane extending between end surfaces of thecasting mold, and with upper parts of the spacer members projectingupward out of the mold space, said spacer members being of metal capableof bonding with the molten ingot metal to form an integrated ingot andhaving longitudinal grooves at the surfaces for abutment with the coreedges which in cross-section mate the cross-section of the core edges sothe spacer members are engaged and guided by said core edges, saidspacer members each having an antiwelding film on the surface thereofopposite the coreengaging surface, initially closing the bottom end ofthe mold, pouring ingot metal into the mold space whereby it bonds tothe spacer members and solidifies within the mold and around the core,effecting downward movement of the solidified metal with the integratedspacer members concurrently with the continued pouring of liquid ingotmetal, exerting a retarding effort upon the spacer members as they passdownward into the mold so that the downward movement of the solidifiedmetal exerts a tension effect along the parts of the spacer memberswithin the liquid metal while maintaining the surfaces of the spacergrooves and the core edges in abutment for thereby guiding the spacermembers in their downward movement, and withdrawing solidified ingotmetal and the integrated spacer members from the cores and therebyproviding an empty channel within the ingot of a size and shapedetermined by the solidification of the metal adjacent the core andwhereby the ingot has internal longitudinal discontinuities formed bythe said antiwelding films in planes substantially at right angles tothe said first plane and each at a distance from the adjacent part ofthe channel determined by the distance from the bottom of the respectivespacer groove to said film on the respective spacer.

2. The method as in claim 1, in which the cores have edges formed byconvergent surfaces, and the grooves in the spacer members are ofcorresponding cross-section for guidedly engaging the said convergentsurfaces at the core edges.

3. The method as in claim 1, in which the cores have edges of roundedcross-section, and the grooves are of corresponding roundedcross-section for guidedly engaging the said rounded core edges.

4. The method as in claim 1, in which a plurality of spaced permanentcores are employed, and spacer members of the bond-integrating metal areplaced between each two adjacent cores, the spacer members havinggrooves in their faces for guidedly receiving the edges of the saidadjacent cores and being held in abutment with the cores.

5. The method as in claim 4, in which a spacer member present betweenand in abutment with two adjacent cores is formed in two parts inabutment with an antiwelding film therebetween and each having a groovefor receiving the edge of the respective core, whereby the formed ingothas a said internal discontinuity provided therein between said channelsand with said discontinuity spaced at distances from the adjacentchannels formed by the said adjacent cores predetermined by thedistances from the respective groove surface to the said film.

6. The method as in claim 5, in which edge pieces are provided, andincluding the employment of end spacer members between the free edges ofthe lateralmost cores and the respective end pieces, with the end piecespresented in abutment with the end spacer members and are integrated bybonding with the solidifying ingot metal, and are lowered concurrentlyduring the downward movement of the solidified part of the ingot, and inwhich anti-welding material is present at the abutting surfaces of theend spacers and end pieces.

7. An apparatus for making an ingot having an inter nal longitudinalchannel, comprising a casting mold open at top and bottom, a platformfor initially closing the lower end of the mold and means forcontrolling the downward movement thereof with the solidified parts ofan ingot supported thereon, means on the platform for engaging andlocating the lower ends of spaced preformed metal pieces to beintegrated into the ingot, a support above the upper end of the mold, afixed core mounted on the support and extending downward into the moldfor contact by molten ingot metal therein, said core being taperedconvergently downward at an angle coordinated to the shrinkage of theingot metal in solidifying and moving downward along the core, the coresupport having openings through which the preformed metal pieces canmove and thence along the fixed core during the descent of the platform,guide means for the said pieces and mounted above the support andincluding rollers engaged with the pieces for urging them into contactwith the edges of the fixed core, and means for pouring ingot metal intothe mold and around the core and metal pieces.

8. An apparatus for making an ingot having a plurality of internallongitudinal channels, comprising a casting mold open at top and bottom,a platform for initially closing the lower end of the mold and means forcontrolling the downward movement thereof with the solidified parts ofan ingot supported thereon, means on the platform for engaging andlocating the lower ends of spaced pre-formed metal pieces to beintegrated into the ingot, a support above the upper end of the mold, aplurality of fixed cores mounted in a row on the support and extendingdownward into the mold for contact by molten ingot metal therein, eachsaid core being tapered convergently downward at an angle coordinated tothe shrinkage of the ingot metal in solidifying and moving downwardalong the core, the cores being at intervals and spaced apart in the rowby the corresponding dimension of the metal pieces and having theirhorizontal crosssections reduced at lateral edges for engagement withconformed surfaces of the pre-formed metal pieces, the core supporthaving openings respectively aligned with the intervals between adjacentfixed cores and through which the pre-formed metal pieces can move andthence 10 move along the fixed cores during the descent of the platform,guide means for the said pieces and mounted above the support andincluding rollers engaged with the pieces for urging them into contactwith the edges of the fixed cores, and means for pouring ingot metalinto the mold and around the cores.

References Cited in the file of this patent UNITED STATES PATENTS705,721 Trotz July 29, 1902 1,894,983 Eppensteiner Jan. 24, 19332,568,525 Waddington et a1 Sept. 18, 1951 2,692,411 Brennan Oct. 26,1954 2,818,618 Winship et al Jan. 7, 1958 2,845,695 Grenell Aug. 5, 19582,878,537 Brennan Mar. 24, 1959 2,950,512 Wilkins Aug. 30, 19602,957,234 Valyi Oct. 25, 1960 FOREIGN PATENTS 13,238 Great Britain Oct.18,. 1886 688,955 Great Britain Mar. 18, 1953

7. AN APPARATUS FOR MAKING AN INGOT HAVING AN INTERNAL LONGITUDINALCHANNEL, COMPRISING A CASTING MOLD OPEN AT TOP AND BOTTOM, A PLATFORMFOR INITIALLY CLOSING THE LOWER END OF THE MOLD AND MEANS FORCONTROLLING THE DOWNWARD MOVEMENT THEREOF WITH THE SOLIDIFIED PARTS OFAN INGOT SUPPORTED THEREON, MEANS ON THE PLATFORM FOR ENGAGING ANDLOCATING THE LOWER ENDS OF SPACED PREFORMED METAL PIECES TO BEINTEGRATED INTO THE INGOT, A SUPPORT ABOVE THE UPPER END OF THE MOLD, AFIXED CORE MOUNTED ON THE SUPPORT AND EXTENDING DOWNWARD INTO THE MOLDFOR CONTACT BY MOLTEN INGOT METAL THEREIN, SAID CORE BEING TAPEREDCONVERGENTLY DOWNWARD AT AN ANGLE COORDINATED TO THE SHRINKAGE OF THEINGOT METAL IN SOLIDFYING AND MOVING DOWNWARD ALONG THE CORE, THE CORESUPPORT HAVING OPENINGS THROUGH WHICH THE PREFORMED METAL PIECES CANMOVE AND THENCE ALONG THE FIXED CORE DURING THE DESCENT OF THE PLATFORM,GUIDE MEANS FOR THE SAID PIECES AND MOUNTED ABOVE THE SUPPORT ANDINCLUDING ROLLERS ENGAGED WITH THE PIECES FOR URGING THEM INTO CONTACTWITH THE EDGES OF THE FIXED CORE, AND MEANS FOR POURING INGOT METAL INTOTHE MOLD AND AROUND THE CORE AND METAL PIECES.